The present invention relates to a handle for implant deployment and to an associated deployment assembly. Delivery devices have long been used for a variety of medical procedures including maintaining passages, cavities or lumens in vessels, organs or ducts, occlusion of such vessels, delivering medical treatments, and other interventions. Today, there is a wide range of intravascular prostheses on the market for use in the treatment of aneurysms, stenosis, and other vascular disorders. Stents, stent grafts, and other vascular prostheses are well known for treating a myriad of diseases and illnesses in vasculature. For percutaneous interventions, many vascular prostheses are inserted into the body within a catheter and deployed at the desired treatment site. The present invention relates to a device for controlled deployment of a vascular prosthesis, such as a stent, stent-graft, filter or occlusion device, for treatment of vascular disorders.
Previously known vascular prostheses can be retained in a catheter delivery configuration using an outer sheath; the prosthesis then expands when the outer sheath is retracted or is subsequently expanded, for example, by a balloon. See, for example, US patent publication number US 2008/0021657 A1, assigned to the assignee of this application. Due to this configuration, several potentially undesirable effects are present during deployment of the prosthesis. Because the outer sheath may be restraining the prosthesis, the frictional force between the prosthesis and outer sheath must be overcome to deploy the stent. The frictional force may be prohibitive to easy sheath withdrawal, and the effort to deliver adequate force may shift the position of the prosthesis.
It is typically desirable that a vascular prosthesis have a high outward acting force to improve in vivo performance. However, this high outward acting force can result in a high frictional force during deployment, particularly at initiation of deployment. Overcoming a high deployment force can be undesirable from safety, ergonomic, and control perspectives, e.g. placement accuracy. A high deployment force requires the user to apply a high force to initiate and complete the deployment, likely with varying forces throughout the deployment. Additionally, prostheses are typically available in multiple configurations, e.g. length and diameter, causing variations in deployment forces required.